In transmission fluid filters, it has been common to make such transmission fluid filters in an assembly that includes a dished base member or pan of plastic or metal and second component made of plastic material with a filter media interposed between the two components. One of the components has an inlet and the other component has an outlet. Typical patents showing such a construction are U.S. Pat. Nos. 4,129,503, 4,136,011, 4,214,781, 4,224,161, 4,264,443, 4,351,550, 4,402,827, 4,417,383, 4,450,081, 4,472,861 and 4,509,340.
In one type of transmission filter, the outlet from a plastic component comprises an outlet tube with a seal thereon. The outlet is positioned in the pump inlet of a transmission. In making such a construction, the seal is mounted on the previously formed outlet tube.
Among the objectives of the present invention are to provide a transmission filter component and the method of making the component wherein the lip seal is not added by an additional or separate operation and wherein the need is eliminated for closely maintaining certain critical dimensions of the outer diameter of lip seal.
In accordance with the present invention, the plastic component is made by providing a first mold cavity having a portion for defining the body of the component and a communicating second cavity for defining the tubular extension, positioning an annular lip seal in the cavity defining the tubular extension, and injecting molten plastic resin in the first cavity and the second cavity to define the plastic component with the lip seal positioned on the tubular extension. Preferably, the method includes defining annular spaced recesses in the second cavity and the step of positioning the lip seal comprises positioning the lip seal between the annular recesses such that when the molten plastic resin is injected, annular ribs are formed in the recesses on the inside of the lip seal adjacent the tubular extension. The resultant plastic component comprises a plastic body, the plastic body comprising a first body portion and an integral tubular portion defining a tubular extension, a lip seal on the tubular body, the plastic body being formed in situ on the lip seal. The tubular extensions include spaced annular ribs formed in situ on the inside of the lip seal.